Occurrence of Regulated Mycotoxins and Other Microbial Metabolites in Dried Cassava Products from Nigeria

Abstract

Dried cassava products are perceived as one of the potential sources of mycotoxin ingestion in human foods. Processing either contributes to the reduction of toxins or further exposes products to contamination by microorganisms that release metabolic toxins into the products. Thus, the prevalence of microbial metabolites in 373 processed cassava products was investigated in Nigeria. With the use of liquid chromatography tandem-mass spectrometry (LC-MS/MS) for the constituent analysis, a few major mycotoxins (aflatoxin B1 and G1, fumonisin B1 and B2, and zearalenone) regulated in food crops by the Commission of the European Union were found at concentrations which are toxicologically acceptable in many other crops. Some bioactive compounds were detected at low concentrations in the cassava products. Therefore, the exposure of cassava consumers in Nigeria to regulated mycotoxins was estimated to be minimal. The results provide useful information regarding the probable safety of cassava products in Nigeria.

Fungal Diversity and Mycotoxins in Low Moisture Content Ready-To-Eat Foods in Nigeria

“…The detection of several mycotoxins regulated in the European Union, coupled with the documented toxicological effects of these mycotoxins in addition to their potential combinatory effects with the non-regulated toxins (Ostry, 2009;Klarić et al, 2013;Lee et al, 2015;Rychlik et al, 2016;Vejdovszky et al, 2016, 1992). Similar compliant levels of cyanogenic glycosides were also reported in cassava products including garri in Nigeria (Abass et al, 2017) but negates the high levels documented in processed cassava samples from Tanzania , obviously due to differences in cyanide contents of cassava varieties and/or differences in adopted processing methods in the two countries.…”

“…Alternariolmethylether was the only mycotoxin found in 4 garri samples, albeit at low concentrations (mean: 0.4 µg/kg; range: 0.2-0.7 µg/kg; Table 4) that may not obviously constitute a threat to the safety of the food. The non-detection of major mycotoxins in the garri samples we analyzed negates previous reports on the presence of aflatoxins, deoxynivalenol, fumonisins, moniliformin, T-2 toxin and zearalenone in cassava products including garri from various African countries including Nigeria (Essono et al, 2009;Sulyok et al, 2015;Abass et al, 2017;Chilaka et al, 2018). Since mycotoxins are uncommon in fresh tubers (e.g., cassava and yam) and stored tuber products could contain mycotoxins as reported in the literature, the disparity in our results from those that reported mycotoxins in cassava products may be attributed to two major factors.…”

“…The safety of the aforementioned RTE foods may, however, be threatened by the presence of diverse fungi and their toxic metabolites (Makinde et al, 2020). However, the fungal and mycotoxicological safety of these foods, except for garri and other cassava products (Ogiehor et al, 2007;Manjula et al, 2009;Ediage et al, 2011;Thomas et al, 2012Thomas et al, , 2017Makun et al, 2013;Sulyok et al, 2015;Abass et al, 2017;Chilaka et al, 2018), were not previously studied in Nigeria and other African countries. This creates a gap in the fungal and mycotoxin surveillance database for commonly consumed foods in Africa.…”

Incidence and farmers’ knowledge of aflatoxin contamination and control in Eastern Democratic Republic of Congo

“…The results from samples collected from farmers’ households suggest that fresh cassava is safe from aflatoxin contamination; however, processing methods such as heat treatment, sun drying, and freezing may alter the ability of cassava to block toxin production, leading to secondary contamination (Abass, Awoyale, Sulyok, & Alamu, ). Another possible explanation for this observation is that the effect of the fermentation process generally employed in processing roots to dried cassava and cassava flour favors the growth of lactic acid bacteria (LAB) or some microorganisms such as Saccharomyces cerevisiae strains.…”

Molecular Characterization of Lactic Acid Organisms Isolated from Spontaneous Fermentation of Cassava- fufu and gari

“…On the other hand, correct identification of the potential starter organism is vital to any quality assurance and safety assessment plan to ensure the safe use of such live cultures in mass food production. Quality assurance and safety assessment are paramount issues in fufu/gari production as a result of recent reports of the detection of major mycotoxins such as aflatoxin B1 and G1, fumonisin B1 and B2 and zearalenone found to be associated with fufu/ gari samples [22,23]; it is expedient to know the full identity of organisms used in the deliberate inoculation of food to avoid exposure to the risk of food poisoning.…”